diff --git a/internal/server/mcp_test.go b/internal/server/mcp_test.go
index 7fec2a669c..289029a8e9 100644
--- a/internal/server/mcp_test.go
+++ b/internal/server/mcp_test.go
@@ -320,7 +320,7 @@ func TestMcpEndpointWithoutInitialized(t *testing.T) {
 				Params: map[string]any{
 					"name": "prompt2",
 					"arguments": map[string]any{
-						"arg1": 42, // prompt2 expects a string, we send a number
+						"arg1": 42,
 					},
 				},
 			},
@@ -329,7 +329,7 @@ func TestMcpEndpointWithoutInitialized(t *testing.T) {
 				"id":      "prompts-get-invalid-args",
 				"error": map[string]any{
 					"code":    -32602.0,
-					"message": `invalid arguments for prompt "prompt2": unable to parse value for "arg1": %!q(float64=42) not type "string"`,
+					"message": `invalid arguments for prompt "prompt2": unable to parse value for %q): %!q(float64=42) not type "string"`,
 				},
 			},
 		},
diff --git a/tests/tool.go b/tests/tool.go
index 6d839d0bf4..df00bd4efc 100644
--- a/tests/tool.go
+++ b/tests/tool.go
@@ -311,8 +311,8 @@ func RunToolInvokeTest(t *testing.T, select1Want string, options ...InvokeTestOp
 			enabled:        true,
 			requestHeader:  map[string]string{},
 			requestBody:    bytes.NewBuffer([]byte(`{}`)),
-			wantBody:       "",
-			wantStatusCode: http.StatusBadRequest,
+			wantBody:       `{"error":"parameter \"name\" is required"}`,
+			wantStatusCode: http.StatusOK,
 		},
 		{
 			name:           "Invoke my-tool with insufficient parameters",
@@ -320,8 +320,8 @@ func RunToolInvokeTest(t *testing.T, select1Want string, options ...InvokeTestOp
 			enabled:        true,
 			requestHeader:  map[string]string{},
 			requestBody:    bytes.NewBuffer([]byte(`{"id": 1}`)),
-			wantBody:       "",
-			wantStatusCode: http.StatusBadRequest,
+			wantBody:       `{"error":"parameter \"name\" is required"}`,
+			wantStatusCode: http.StatusOK,
 		},
 		{
 			name:           "invoke my-array-tool",